This application is based on application No. 094073 filed in Japan on Mar. 30, 2000, the content of which incorporated hereinto by reference.
This invention relates to a method which calculates and outputs remaining capacity of a battery to an electronic device changing into hibernation when the remaining capacity of the battery becomes hibernation changeover capacity, especially the method which corrects the remaining capacity of the battery to output to the electronic device accurately.
In an electronic device such as a computer, It occurs a problem that a power source is powered down during its processing. For example in a case of a word processor, a writing document can be lost when the power source is powered down during its processing to write a document. Further more, it can occur a problem when software is not logged off in proper. In the case of a computer having a battery as a power source, it is necessary to be powered down to prevent over-supply, when the remaining capacity of the battery becomes little and cannot supply power. Thereby, it can occur the problems mentioned above, if the power source is powered down after the remaining capacity of the battery becomes little.
To solve these problems, a technology in which the power source is powered down with changeover into hibernation, when the remaining capacity of the battery decreases and becomes lower than hibernation changeover capacity, was developed. The hibernation prevents the problems cause of powered down, with saving data in processing to a memory such as a hard disc drive before the power source powered down. An electronic device such as a computer achieving it powers down with changeover hibernation, when the remaining capacity of the battery as a parameter becomes the hibernation changeover capacity. The battery side outputs the remaining capacity to the electronic device such as a computer with calculating.
The battery side calculates the remaining capacity with subtracting supplied capacity from full-charged state to output the remaining capacity to the electronic device. However, the calculated remaining capacity in the battery side does not always equal to practical remaining capacity of the battery. Therefore, the battery side corrects the remaining capacity with detecting battery voltage. FIG. 1 shows a graph of a state, which corrects the remaining capacity with the battery voltage. FIG. 1 shows a character decreasing the battery voltage in accordance with power supply and a character correcting the remaining capacity. A correcting method of FIG. 1 corrects the remaining capacity of the battery to 0% when the battery voltage becomes 0% detecting voltage in accordance with power supply from the battery.
The correcting method mentioned above can prevent battery from over-supplying with correcting the remaining capacity of the battery around 0% certainly. However, the method correcting the remaining capacity in such way cannot always log off electronic devices such as a computer with changeover hibernation. For example, in the case the battery outputs the remaining capacity with sampling time at point a and point b of FIG. 1, it does not change into hibernation cause the remaining capacity is higher than the hibernation changeover capacity, and it cannot change into hibernation cause the remaining capacity is 0% which means supplying out completely, in the correcting method of FIG. 1, the remaining capacity drops to 0% in an instant, so that it cannot change into hibernation.
A method, which does not correct the remaining capacity of the battery to 0% in an instant, was developed (Japanese Patent Laid-Open Publication No. Toku-Kai-Hei 5-87896 (1993)). As shown in FIG. 2 and FIG. 3, the method mentioned above in the Application corrects the remaining capacity of the battery at point A, B, C and D to measure the battery voltage. Voltage is set in advance corresponding to each of the remaining capacity of the battery when the battery voltage becomes the voltage at point A, B, C and D, and the remaining capacity of the battery is corrected to the remaining capacity at point A, B, C and D when the battery voltage becomes the voltage.
As shown in FIG. 2 and FIG. 3, the method correcting the remaining capacity with the battery voltage can calculate and correct remaining capacity similar to the actual remaining capacity. However, it can occur not to change into hibernation properly, even in the method correcting the remaining capacity to output the electronic device.
For example, at the point A and B of FIG. 3, when the battery outputs the remaining capacity to the electronic device, the remaining capacity is higher than the hibernation changeover voltage at point a, so that the electronic device does not change into hibernation, next even though the remaining capacity is lower than the hibernation changeover voltage at point b, the remaining capacity has already got down to 0%, the electronic device becomes a state which cannot change into the hibernation.
The present invention has developed to achieve the object to solve the problems. The important object of the present invention is to provide a method of correcting battery remaining capacity, which can log off an electronic device with changing into hibernation certainly, when the remaining capacity becomes little. The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
A remaining capacity of a battery correcting method of the present invention outputs the remaining capacity with calculating to an electronic device which change into hibernation when the remaining capacity of the battery becomes lower than hibernation hangover capacity. The method of correcting battery remaining capacity decreases the remaining capacity with predetermined gradient after corrected to the hibernation changeover capacity, when the remaining capacity at battery voltage being decreasing to 0% detecting voltage is higher than the hibernation changeover capacity. In addition, when the remaining capacity at decreasing to 0% detecting voltage is lower than the hibernation changeover capacity, the remaining capacity is decreased with predetermined gradient.
The invention mentioned above has an advantage that it can log off the electronic device certainly by changing hibernation when the remaining capacity of the battery becomes little. It causes that the method of correcting battery remaining capacity decreases the remaining capacity with predetermined gradient after corrected to the hibernation changeover capacity, the remaining capacity is decreased with predetermined gradient, when the remaining capacity at decreasing to 0% detecting voltage is higher than the hibernation changeover capacity, and when the remaining capacity at decreasing to 0% detecting voltage is lower than the hibernation changeover capacity.
In the method of correcting battery remaining capacity according to the present invention, preferably the 0% detecting voltage is set to voltage that the remaining capacity of the battery becomes 2-5%.
In addition, in the method of correcting battery remaining capacity according to the present invention, preferably the gradient to decrease the remaining capacity after detecting the 0% detecting voltage is set a constant gradient of the remaining capacity decreasing value per time.
Further, in the method of correcting battery remaining capacity according to the present invention, preferably the gradient to decrease the remaining capacity of the battery after detecting the 0% detecting voltage is set value that the remaining capacity becomes 0 within 10-60 seconds.
Further, in the method of correcting battery remaining capacity according to the present invention, preferably after detecting the 0% detecting voltage, consumed power of the electronic device is calculated, and the gradient to decrease the remaining capacity is determined by the consumed power.
Further more, in the method of correcting battery remaining capacity according to the present invention, preferably the gradient to decrease the remaining capacity after detecting the 0% detecting voltage is set to make decreasing time that the remaining capacity of the battery becomes 0 longer than a period of sampling time to output the remaining capacity to the electronic device.